// 实现这个项目的构建任务
const { src, dest, parallel, series, watch } = require('gulp')

const del = require('del')
const loadPlugins = require('gulp-load-plugins')
const browserSync = require('browser-sync')

const plugins = loadPlugins()

//创建开发服务器
const bs = browserSync.create()

const data = {
  menus: [
    {
      name: 'Home',
      icon: 'aperture',
      link: 'index.html'
    },
    {
      name: 'Features',
      link: 'features.html'
    },
    {
      name: 'About',
      link: 'about.html'
    },
    {
      name: 'Contact',
      link: '#',
      children: [
        {
          name: 'Twitter',
          link: 'https://twitter.com/w_zce'
        },
        {
          name: 'About',
          link: 'https://weibo.com/zceme'
        },
        {
          name: 'divider'
        },
        {
          name: 'About',
          link: 'https://github.com/zce'
        }
      ]
    }
  ],
  pkg: require('./package.json'),
  date: new Date()
}

const clean = () => {
  return del(['dist'])
}

const style = () => {
  return src('src/assets/styles/*.scss', { base: 'src' })
    .pipe(plugins.sass({ outputStyle: 'expanded' }))
    .pipe(dest('dist'))
    .pipe(bs.reload({stream: true})) //以流的方式去浏览器推
}

const script = () => {
  return src('src/assets/scripts/*.js', { base: 'src' })
    .pipe(plugins.babel({ presets: ['@babel/preset-env'] }))
    .pipe(dest('dist'))
    .pipe(bs.reload({ stream: true }))
}

const page = () => {
  return src('src/*.html', { base: 'src' })
    .pipe(plugins.swig({ data, defaults: { cache: false } })) // 防止模板缓存导致页面不能及时更新
    .pipe(dest('dist'))
    .pipe(bs.reload({ stream: true }))
}

const image = () => {
  return src('src/assets/images/**', { base: 'src' })
    .pipe(plugins.imagemin())
    .pipe(dest('dist'))
}

const font = () => {
  return src('src/assets/fonts/**', { base: 'src' })
    .pipe(plugins.imagemin())
    .pipe(dest('dist'))
}

const extra = () => {
  return src('public/**', { base: 'public' })
    .pipe(dest('dist'))
}

//创建服务器,yarn gulp serve: 启动服务器
//watch:代码修改后自动编译,第一个参数产生任务的构建路径,第二个参数指定的任务函数
//watch触发后,dist文件会被覆盖掉,browser-sync自动同步到浏览器
const serve = () => {
  watch('src/assets/styles/*.scss', style),
  watch('src/assets/scripts/*.js', script),
  watch('src/*.html', page),
  //图片,字体不需要监听,直接再baseDir去依次取值就可以了
  // watch('src/assets/images/**', image),
  // watch('src/assets/fonts/**', font),
  // watch('public/**', extra),
  //数组监听页面改变,watch箭头变化,执行bs.reload同步到浏览器但是不构建,上面那种写法是构建了的
  watch([
    'src/assets/images/**',
    'src/assets/fonts/**',
    'public/**'
  ], bs.reload)

   bs.init({
     notify: false,  //取消右侧的提示
     port: 8080,  
     open: true, //取消自动打开浏览器
     /** 另外一种写法,文件更新后,不写files,在每个文件都加入bs.reload,效果相同 */
     files: 'dist/**',  //指定下的文件修改自动刷新页面
     server: {
       baseDir: ['dist', 'src', 'public'], //指定网站的根目录
       routes: {        //可以指定到同一个目录下去
         '/node_modules': 'node_modules'  //将'node_modules'开头的文件指到项目下的node_modules去
       }
     }
   })
}

const compile = parallel(style, script, page)

// 上线之前执行的任务
const build =  series(
  clean,
  parallel(
    compile,
    image,
    font,
    extra
  )
)

const develop = series(compile, serve)


module.exports = {
  style,
  page,
  clean,
  build,
  serve,
  develop
}
